AES E-Library

Fixing the Phantom Center: Diffusing Acoustical Crosstalk

When two loudspeakers play the same signal, a “phantom center” image is produced between the speakers. However, this image differs from one produced by a real center speaker. In particular, acoustical crosstalk produces a comb-filtering effect, with cancellations that may be in the frequency range needed for the intelligibility of speech. We present a method for using phase decorrelation to fill in these gaps and produce a flatter magnitude response, reducing coloration and potentially enhancing dialogue clarity. This method also improves headphone compatibility, and it reduces the tendency of the phantom image to move toward the nearest speaker.